About Squamish Crag Conditions

The crags covered by this site are on the unceded traditional territory of the Sḵwx̱wú7mesh Úxwumixw (Squamish Nation), who have lived on and cared for these lands and waters since time immemorial. To learn more, visit the Squamish Nation website. To learn about Indigenous territories and languages across BC, see the First Peoples' Language Map.

Squamish Crag Conditions combines each sector's compass-facing wall direction with live sun position and recent weather to give a rough sun/shade status and a 0–100 “dry score” heuristic for climbing sectors around Squamish, BC. It's meant to help you decide where to head, not to replace your own judgment at the crag.

Crag and sector locations come from OpenBeta's public climbing database. Weather — rainfall, current conditions, and the short-range forecast — comes from Environment and Climate Change Canada's public MSC GeoMet API, read from the Squamish Airport station. Each sector page, and each area's own page, also shows a modeled current temperature and condition specific to that location, from Environment Canada's GEM-HRDPS model via Open-Meteo, plus a comparison of that location's estimated rain against the airport's, from Environment Canada's HRDPA precipitation analysis, and a modeled hourly precipitation chart from that same GEM-HRDPS model, shown alongside the airport's real hourly chart. There's also a location-specific forecast for the coming week — temperature, condition, and a precipitation chart — blending Environment Canada's GEM-HRDPS model for the first day or two with the longer-range ECMWF model beyond that, since GEM-HRDPS alone only looks about two days ahead; days sourced from ECMWF are marked, since they're a coarser, area-level estimate rather than specific to the exact sector. Cloud cover for the dry score's sun credit comes from the ECMWF model, also via Open-Meteo. The embedded maps use OpenTopoMap tiles, © OpenStreetMap contributors. The Sea-to-Sky highway camera image comes from DriveBC / DataBC, released under the Open Government License – British Columbia.

The dry score starts at 100 and combines three things: how much rain fell in the last 72 hours, how long ago it stopped, and how much direct sun a sector has had since then. If the airport gauge shows it raining right now, the score is capped as “wet” regardless. It's a heuristic, not a measurement — sun exposure and drainage both vary a lot within a single sector, and the score can't see that.

Drying time is weighted by the airport's temperature and humidity. An hour at 10°C or warmer counts in full, colder hours count for less, and hours at or below freezing don't count at all. Hours when the air is saturated (95% humidity or more) count for half. So a cold, damp day recovers much more slowly than a warm, breezy one.

Sun credit only counts when the sun is actually getting through. Each hour of direct sun on the wall is reduced by the cloud cover the ECMWF weather model shows for that area, and dropped entirely in fog or drizzle (95% humidity or more at the airport). If the model is unavailable, the humidity check still applies.

A snowflake next to the score means there's been snow at the airport recently or it's below freezing; a thermometer means it's near freezing. The score doesn't model snowmelt, ice, or seepage, so treat it as a rough guide in those conditions.

Best conditions right now (the default) ranks sectors by dry score, highest first — sectors tied on score put sun-facing ones ahead of shade-facing ones, so it's a quick answer to “where should I go right now.” Sun-facing first and Shade-facing first reorder by sun/shade status instead, useful on a hot day when shade matters more than dryness. Name and Area just sort alphabetically. None of these change the underlying dry score or sun/shade status, only the order sectors appear in.

Aspect data is mostly unverified. Only sectors with a manually curated wall direction get a real sun/shade calculation — everything else is marked unverified rather than guessed, and its dry score renders with a ~ prefix since it's missing the sun-recovery part of the formula.

Sun/shade status is a rough geometric estimate, not a live view of the wall. It compares the sun's real compass position right now against each sector's curated wall direction, and counts anything within 90° either side as “in sun” — it has no way to know about terrain that blocks the sun despite favorable geometry, like a wall shadowed by a canyon or ridge. It also shifts with the seasons: the sun's path across the sky is lower and shorter in winter, higher and longer in summer, so a sector that's sunny most of the day in August may only catch a narrow window in December. The badge always reflects the sun's actual position for right now, not a fixed assumption.

The dry score and rain history are one regional reading, not per-crag. Environment Canada's station coverage in the Squamish valley is sparse relative to individual crags, so a sector in a rain shadow or a local microclimate won't be reflected there. The modeled current temperature/condition shown on each sector page is location-specific and doesn't share this limitation — though it can visibly differ from the regional forecast above for the same reason (elevation and location), which is expected, not an error. The rain comparison badge is similarly location-specific, but it's shown for context only — it's a blend of radar, gauge, and model data rather than a direct measurement, so the dry score itself still uses the Squamish Airport gauge, not this estimate.

Cloud cover is modeled, not measured. The airport station doesn't report cloud, so the sun credit uses the ECMWF model's cloud cover — the one modeled input to the dry score. It's an area-level estimate (its grid squares are about 9km across), not a view of a specific wall.

Winter is where the score is weakest. Snow on ledges and the top-out can keep rock wet for days after the last snowfall, ice can form on rock that looks dry, and after a few months of wet weather some walls seep for weeks no matter what the last three days looked like. The airport also sits near sea level, while many crags are higher and colder, so a crag can get snow while the airport gets rain. Trust what you see over the number.

The forecast is Environment Canada's own, shown separately from observed conditions — it's a forecast, not a measurement, and is never blended into the dry score or the sun/shade badges.

The highway camera shows the valley, not the crag. It's a quick visual gut-check on regional conditions, not a view of any specific sector — treat it the same way you'd treat glancing out the car window on the drive in.

Use all of it at your own discretion, and trust what you see when you get there over what this site says.